Backlash in OMC lower drive

[maintenance_planner]

With my 1988 OMC 5.7 outdrive in gear and ideling a little rough, the lower gears clunck from the backlash every time the engine surges. Rev the engine to about 1200 RPM's and you don't get it, put the gears in neutral or the boat in the water and you don't get it? Any suggestions?

 

[Scali]

Re: Backlash in OMC lower drive

this is a very common issue inolving the throttle cable adjustment . OMC replaced many gearsets after gear clashing & failure as a recall under warranty .<br />It's often very diffuicly to adjust Cobra throttle cables properly & they slip out of gear inbto reverse creating your clunking sound.<br />This is not a good thing to use the boat this way & you'll end up blowing the drive.<br />Do a Google & try to update your cable & or have someone do it for you, it's not easy.<br />Not all Cobras were affected, the king Cobras I believe were better.<br />& yes I owned a cobra drive boat I sold for a loss after the engine hydrolocked because the throttle cable was so tight I couldnt find " N " & she stalled & took a drink through the exhaust..<br />Good luck, Mercruisers are far better outdrives.<br />The Cobra fiasco was part of OMC's demise..

 

[JB]

Re: Backlash in OMC lower drive

I/O topic

 

[whywhyzed]

Re: Backlash in OMC lower drive

if it doesn't do it in the water I'm not sure I'd get too worried about it.. although every Cobra owner should be conscious of the shift cable adjustments and this site has become the base reference:<br />www.hastings.org/~stuart/cobra/

 

[maintenance_planner]

Re: Backlash in OMC lower drive

Thank you all for your reply, after talking to a local ex-factory OMC repair person and a authorized mercrusier repair shop, the problem has been determined to be the stainless prop (louder) is spinning freely and when the RPM drops from the engine loping, the prop speed actually out runs the input shaft speed. This is why it don't show up in the water where the prop has friction. Some mercrusier has been noted to do it, infact that mercrusier engineers had put an article out to their dealers years ago.